1. Technical Field
The present invention relates to a print control apparatus and a print control method.
2. Related Art
Ink jet printers are known that include a plurality of nozzles and dispense ink of a plurality of colors through respectively corresponding nozzles to thereby print an image on a printing medium. Such printing is performed on the basis of print data that defines an on/off setting of dots with respect to the ink of each of the plurality of colors and each pixel. The print data is, for example, binarized so as to define the on/off setting of the dots. Accordingly, a process called gray scale conversion or halftone processing is performed to generate the print data from the image to be printed.
In addition, for example JP-A-2007-116433 discloses an image processing apparatus in which a 5 color/4 color selection signal indicates whether to output a toner image composed of five colors, namely cyan, magenta, yellow, black, and light black (CMYKL) (first recording mode) or a toner image composed of four colors of CMYK (second recording mode). The image processing apparatus is configured to perform pseudo-halftone processing of a dot screen with respect to three colors of CMY in the first and second recording modes, perform pseudo-halftone processing of a line screen with respect to KL in the first recording mode, and perform pseudo-halftone processing of the dot screen with respect to K in the second recording mode.
In the ink jet printer, a dither mask having a characteristic of generating random noises that are difficult to recognize with human eyes is often employed for the gray scale conversion to generate the print data. Although the gray scale conversion that employs such a dither mask provides high picture quality when a content that require relatively high gradation level is printed, when the user requires sharpness as picture quality, the gray scale conversion often fails to satisfy such a requirement.
Now, the ink jet printer that dispenses ink, which is a liquid, has an intrinsic drawback in that the ink of different colors interfere with each other upon being dispensed onto the printing medium, thereby producing “blur of colors”. When gray scale conversion based on another method is employed in order to attain a sharp picture, instead of the gray scale conversion that employs the dither mask, the blur tends to appear on the printing medium in regular placement. The blur can be construed as a type of image degradation, and such blur that regularly appears is readily recognized visually as a pattern, which leads to degraded evaluation from users in terms of picture quality.